Railway traffic controlling apparatus



Juhe 30, 1 936.

F. H. NICHOLSON RAILWAY TRAFFIC CONTROLLING APPAR ATI JS Original Filed July 25, 1934 F 2? yr DJ 18 m CXIBX BF nulllnn H F C'X J12 v v vi 7f Code Seleotion CT awn-fi s B "l F INVENTOR Frank HNiclzol on HIS ATTORNEY Patented June 30, 1 936 uNiTEosTA Es PATEN "OFFICE aosamamwu mime con-momma mana'ms Frank H. Nicholson, Wilkinsburg, assignor to The Union Switch & 3181B] Company,

Swlsavale, Pm, a corporation Pennsylvania Application July 25, m4, Serial No. 13 .951

Renewed October 9'.

1:: Claims. (com-s4) My invention relates to railway traflic controlling apparatua and more specilcally to apparatus for controlling wayside and cab signals by means of coded track circuit current.

One feature of my invention is the provision of simple and inexpensive means for transferring from a normally effective source of coded track circuit energy to an auxiliary source of coded track circuit energy in case of failure of the normally eifective source.

I willdescribe one form of apparatus embodying my invention, and will then point out the novel features thereof in claims. I r

The accompanying drawing is a diagrammatic view showing one form of apparatus embodying my invention.

Referring to the drawing, the reference char- 'acters l and l designate the track rails of a section of track 2! normally supplied with current from a track transformer T located at one endof the section. Connected across the rails at the other end of the section is a direct current code-following track relay TR. When the rails of section 2-3 are supplied with coded unidi.-

rectional current and the section is'imoccupied,

,relay TR follows the impulses of the code, alternately closing its contacts 4-5 and 4-4 at a rate determined by the code being received. Each time that front contact H closes, an impulse of direct current from a source which is not shown but which has the terminals B-Cds supplied to the upper half of the primary winding of the decoding transformer DT. Similarly, each time that back contact 4-8 closes, a direct current impulse in the reverse direction is supplied to the lower half of the primary winding. This operation of relay TR causes an alternating po-. tential of the code frequency to be induced across the terminals of the secondary winding 20.

If the code being received by relay TR com- & prises current impulses recurring at the rate of 180 times per minute for example, decoding relay .1? will be energized because of the selective tuning which is accomplished by means of the con- Control of suitable signaling appaartus such as .waysidesignals, and the selection. of .the code .whichisordinarilyappliedtothenctioninthcrear of location 2 maybe accomplished over contact fingers such as land I of relays H and F, respectively, in well-known manner. The apparatus described so far is well known and. is believed to require no'further detaileddescription. 8

I shall next describe the code-feeding apparatus for the section 2-4.

The reference character CT designates a cod- 0 ing device or code transmitter energized fromthe source B-C and arranged to be in operation 10 at all times, so that contacts I and 80 thereof constantly close and open at the rate, of. and 80 times per minute, respectively. The code selection apparatus is not shown in detail, but it will be'understood that this portion of th apl5.

paratus functions in theusual and well-known manner whereby a circuit will be completed over one or the other of wires sor III, as determined by traflic conditions in advance. For example, when'the advance block ls-unoccupied, wires will be closed and wire I II will be open, whereas with the advance block occupied, wire III. will be;

closed and wire 8 will be open.

Atlocation 3 is an alternating current source having the terminals BX-CX, which source is 5 used for energizing the track transformer T, as

well asthe alternating current power-oi! relay P0. The power-off relay is maintained energized as long as the source BX-CX remains effective. Normally, therefore, if the advance section is unoccupied, the primary winding ls'or transformer T is supplied with alternating current periodically interrupted at 180 code over a circuit extending from one terminal Bxof the source, contact 180 of transmltterC'l, wires 9 and 3 ll, front point of contact I! of relay PO, and winding It, to the other terminal CX ofthe same source. If the advance section is occupied, windmg I: W111 receive alternating current periodf ically interrupted at 80 code over this same ciro cuit, with the exception thatLcont'act [80 and wire 9 will now be replaced by contact 88 and wire II.

Considering first the function of the secondary winding ll, this winding will impress periodically 4,5

interrupted alternating current across the ter-r minals of the full-wave rectifier R, whereby pe-- riodically interrupted pulsating. unidirectional V current will be caused to flow in therails |l-. for energizing the track relay TR. Assuming that 60 the instantaneous polarity of the right-hand terminal'of winding i4 is positive, then at that instant, cunent will flow over. a circuit which includesele'inent 2 8 of rectifier R, winding ll, wires at, e dgamem circuit, wiresll man, and so element 23, to the left-hand terminal of winding l4. At the instant when the left-hand terminal of winding I l becomes positive, the current will flow over a circuit which includes element 24, winding I5, wires 26 and 27, the track circuit, wires 2| and 22, and element 25, to the right-hand terminal of'winding M. It will be apparent, therefore, that both. half-waves oi the alternating current output of winding it are rectitled.

Considering next the function of the secondary winding l5, this winding provides half-wave rectification only, its rectified half-wave output being superimposed on the rectified full-wave output of winding Id. The current path from winding l5, at the instant when the right-hand terminal of the winding is positive, includes wires 26 and 21, the track circuit, wires 2i and 22, and rectifier paths 25-28 and 23-24 in parallel. The combined output of windings it and I5 results in a wave oi current in the rails l and i this wave being unidirectional in character for operating the track relay TR, and also having undulations or variations therein for eiiective control 01' locomotive-carried cab signaling equipment. That is, the rectified rail current impulses are all of one polarity so that the direct current track relay TR. may be controlled thereby. However, these individual impulses entail also a variation of the current, so that considering a single impulse, at one instant the current is building up, and at another instant is dying down. Since the locomotive equipment is sensitive to a variation of the rail current, though not to the actual magnitude of this current,'the locomotive equipment will respond to the. above variations.

It will be understood that winding i5 alone is suiiicient to provide both the unidirectional and varying character of the track circuit cur rent. However, the use of winding id renders the system more eiiective, since the average value of the rail current as well as the magnitude of the variations therein are both" increased thereby. Obviously, transformer T need not have independent primaryand secondary windings, but may be of the auto-transformer type, if desired.

Should the alternating current source BX-CX fail for any reason, relay P will immediately release, disconnecting winding it! from the code transmitter contacts, and closing an energizing circuit for the code-repeater or auxiliary relay CR over the back point of contact [2 of relay PO. Y

The circuit for relay CR may betraced from one terminal B of a standby source, one or the other of contacts I80 or 80 of transmitter CT as determined by traflic conditions in advance, wire 9 or wire I, wire ll, back point of contact I2, wire l6, and the winding of relay CR, to the other terminal C of the source. The terminals B-C may be terminals of the standby source S, which is illustrated.

Since the circuit for relay CR includes a code transmitter contact, this circuit will be periodically interrupted at the proper code frequency,

so that relay CR will follow the code and will" reflect the operation of the transmitter CT. Each time that relay CR picks up, an impulse of direct current from the emergency source S will be supplied to rails I and I, over the front contact ll of relay CR. Therefore,-relay TR will continue to operate, after source BX-CX fails, so that the wayside signaling apparatus will be effective to control the movement of trains, even aosaeoe current component in the code current supplied from source S. The source S and rectifier R are poled in such manner with respect to each other as to prevent a short-circuit on the source through winding l when contact I1 is closed.

As soon as current from source BX-CX is restored, relay P0 will pick up, restoring coded alternating current to-winding l3 of transformer T and opening the circuit for relay CR. As soon as relay CR releases, source S will be disconnected at front contact I1, and the system will continue to operate in the normal manner described above. If it is desired to incorporate broken-down insulated rail joint protection into the system, relay TR may be a two-position polarized codefollowing relay, biased to the position in which back contact' i-S is closed when the relay is either deenergized or is energized with unidirectional current of reverse polarity, for example. Under this condition, rectifier R and source S should be poled in such direction that unidirectional current of normal relative polarity will be supplied to the rails of section 2-3, both at such times as the main source BX-CX is active, and at such times as the emergency source S is active. The rails of the block section-in advance as well as in the rear of section 2-3 would, under the above condition, be normally supplied with unidirectional current of reverse relative polarity, so that'if the block joints at location 2 or 3 should break down, the incoming current from the adjoining block will be of improper polarity for picking up relay TR.

Due to the fact that the code-repeating relay CR remains normally deenergized, and is called upon to operate only in the event of a failure of the main source BX-CX, this relay more, it should be noted that due to the arrange! ment of windings l8 and I5, rectifier R, and

source S, no relay contacts whatever are included in the normal circuit which feeds current to the rails I and i Due to the fact that contacts in the track feed circuit are ordinarily called upon to carry currents amounting to several amperes, the consequent burning at these contacts may introduce resistance into the feed circuit, or shorten the life of the contacts, rendering the operation of the system less reliable. Therefore, the apparatus disclosed eliminates the troubles ordinarily incident to the use of relay contacts in the track feed and provides a reliable and relatively simple and inexpensive system for taking care of power failures. It will be understood that the novel features of my invention are not limited to a system of the code type, as the invention can be used, as well, in a system using uncoded current having both unidirectional and trackway device controlled by energy received from the rails of said section and responsive to coded uni-directional current, wayside signaling apparatus controlled by said device, a main source of alternating current, a rectifier, means includaccuses ing said main source and an reconsim at times pplying the rails of said section with varying unidirectionalcurrent for controlling said device as well as for controlling train-carried signaling a apparatus, an auxiliary source of direct current, means for at other times supplying the rails of said section with current from said auxiliary source, and means for coding the current supplied to said rails in accordance with tramc conditions in advance of said section. v

' 2. In combination, a section of railway track, a a direct current code-following track relay for said section. wayside signaling apparatus controlled by said track relay, a main source of alternatins current, a rectifier, means including said main source and said rectifier for supplying the rails of said section with varying unidirectional ,current for controlling said track relay as well as for controlling train-carried signaling apparatus, an auxiliary source of direct current, means for supplying current from said auxiliary source to said rails efiective upon the failure of said alternating current source, and acoding device for coding the current supplied to said rails. 3. In combination. asection of railway track, a direct current code-following track relay for said section, a main source of alternating current, a transformer having a primary winding energized from said main source and having a sec- 'ondary winding, a full-wave rectifier having its input terminals connected across said secondary winding, means for supplying the rails of said sec-- tion with current from-the output terminals of said rectifier, an auxiliary source'of direct current. an auxiliary relay, means controlled by said auxiliary relay effective upon the failure of said main source for supplying said rails with current from said auxiliary source, and a coding device for coding the current supplied to said rails.

4 In combination, a section of railway track, a direct current code-following track relay for said section, a main source of altemating' current, a

transformer having a primary and a secondary winding, a power-off relay energized form said main source, a circuit including afront contact of said power-off relay for energizing said primary winding from said main source, a full-wave rectifier having its input terminals connected across 1 said secondary winding, means for supplying the rails of said section with current fromthe output terminals ofsaid rectifier, an auxiliary source of direct current, an auxiliary relay, a circuit'ineluding aback contact of said power-oifrelay for energizing said auxiliary relay, means including a front contact of said auxiliary relay for supplying said rails with. current from said auxiliary source, and a-coding device for coding the current supplied to said rails. 4

5. In combination, a section of railway track, a direct current track relay for said section, a main source of alternating current, a transformer, a power-ofi relay energized from said main source, 7 a circuit including a front contact of said-powers oif relay for energizing said transformer from said main source, a rectifier, means including said rectifier for supplying current from said transformer to the rails of said section, an auxiliary source of direct curren g an auxiliary relay, means including a back contact of said power-off relay for energizing said auxiliary relay, and meansiix =cluding a front contact of said auxiliary relay f( r supplying said rails with 'current'from said auxiliarysource. E. I

6. In combination, a section of railwaytrack, a

.75 direct-current trackrelayfor saidsection,

auxiliary source across the rails of said track.

source of alternating current, a transformer enerigized from said main source, a rectifier, means including said rectifier for supplying both fullwave and half-wave rectified current from said transformer to the rails of saidsection, an auxiliarysource of direct current, and means effective upon a failure of said main source for sunplying said rails with current from said auxiliary source. c y

v 7. In combination, a section of railway track, a direct current track-relay for said section. a main source of alternating current, a transformer hava primary winding energized from said main so and having two secondary windings, a fullwave rectifier connected across the terminals of 15 one of said secondary windings, means including i the other of said secondary'windings and the output terminals of said rectifier for supplying currentto the rails of said section, an auxiliary source of direct current, and means effective upon 20 a failure of said main sourcefor supplying said rails with current from said auxiliary source.

8. In combination, a section of railway track, a

, direct current track relay for said section, a main source of alternating current,a transformerhav- 26 ing a primary and two secondary windings, a power-on relay energized from said main source,

a circuit including a front contact of said poweroif-relay for energizing said primarywinding from said main source, a full-wave rectifier connected 80 across the terminals of one of said secondary windings, a circuit including the output terminals of said rectifier and the other of said secondary windings for supplying current to the rails of said section, an auxiliary source of direct current, an 88 auxiliary relay, a circuit for energizing said auxiliary relay including a back contact of said power-oil relay, and a circuitlncluding afront contact of said auxiliary relay for connecting saidv 9. In combination, a section of railway track, I a direct cin'rent code-following track relay for said section, a-main source of alternating current, a transformer having a primary and a secondary winding, a power-off relay energized from said main source, a coding device, means including a front contact of said power-off relay and a contact'of' said coding device for energizing said primary winding from said main source, a' rectifier, means including said secondary winding and said rectifier for supplying current to the rails of said section, an auxiliary source of direct current, an

auxiliary relay, means including a back contact of 'said .po wer-oif relay and said contact of the coding device for energizing said auxiliary relay, andv means including a front contact of said auxiliary relay for supplying said rails with current from said auxiliary source.

10. In combination, a section of railway track, a direct current code-following track relay for 60 said section, a main source of alternating current, a transformer having a primary and two secondary windings, a power-oil relay energized from said main source, a coding device, means including a front contact of said power-off relay-and 65 a contact oi! said coding .device for energizing said primary winding from said main source, a full-wave rectifier having its input. terminals connected across one of said secondary windings, a circuit including the output terminals of said 70 rectifier and the other of said secondary windings for supplying current to the rails of said section, an auxiliary source, of direct current, an auxiliary relay, means including a back contact of said power-oifrelay and said contact of the coding device-for energizing said auxiliary relay, and means including a front contact of said auxiliary relay for supplying said rails with current from said auxiliary source.

11. In combination, a section of railway track, a main source of varying current, a transformer energized from said main source, a rectifier, means including said rectifier for supplying both full wave and half wave rectified current from said transformer to the rails of said section, an auxiliary source of current, and means effective upon a failure of said main source for supplying said rails with current from said auxiliary source.

12. In combination, a section of railway track, a main source of alternating current, a rectifier, means including said rectifier for supplying both full wave and half wave rectified current from said main source to the rails of said section, an auxiliary source of current, and means effective upon a failure of said main source for supplying said rails with current from said auxiliary source.

13. In combination, a section of railway track, a source of varying current, a transformer energized from said source, and means including a rectifier for supplying both full waveand half wave rectified current from said transformer to the rails of said section.

14. In combination, a section of railway track, a source of varying current, and means including a rectifier for supplying both full wave and half wave unidirectional current from said source to the rails of said section. I

15. In combination, a section of railway track, a source of varying current, a transformer having an input winding energized from said source and having a first and a second output winding, and means including a rectifier connected with said two output windings so as to supply full wave rectified current to the rails or said section from said first output winding through said second output winding and to supply halt wave rectified current to the rails of said section from said second output winding. 5

16. In combination, a section of railway track, a source of varying current, a transformer having a primary winding energized from said source and having a first and a second secondary winding, a full wave rectifier having its input'termil0 nals connected with said first secondary wind ing, a connection from one output terminal oi. said rectifier to one rail of said track, and a connection from the other output terminal of said rectifier through said second secondary winding 5 to the other rail of said track.

17. In combination, a section of railway track, a source of varying current, a transformer having an input winding receiving energy from said source and having a first and a second output 20 winding, and means including a rectifier connected in parallel with said first output winding and in series with said second output winding for supplying both full wave and half wave rectified current to the rails of said section.

18. In combination, a section of railway track, a source of varying current, a transformer having an input winding receiving energy from said source and having a first and a second output winding, a full wave rectifier, a first circuit including said rectifier and said first output winding connected in parallel for supplying full wave rectified current to the rails of said section, and a second circuit including said rectifier and said second output winding connected in series for V supplying half wave rectified current to the rail of said section.

FRANK H. NICHQLSON. 

